I received my Arduino back in 2009 at LCA. I've tinkered with it a bit and really haven't had to many bright ideas about what to use it for. I've been cutting some code recently for the magic lantern project, but the short version is, I need to place another order to get Atmel328s because the Atmel168s ran out of stock.
Anyhow, in the last order I to Little Bird Electronics I got some DS1077 programmable oscillators. They are a tiny little 8 pin SOIC. Been reading up about how to use them now. They have a I2C bus and there is a library for Arduino to bitbang out the commands to send out over I2C. Benlemasurier's DS1077 Library looks like it should do the job nicely. Now to find a carrier board to solder them up to, or perhaps make one...
What will I use them for? Well, a general coverage receiver is the obvious project. I think that that will be a while off yet, but its on the cards.